There are people on this board running the stamped steel rockers to 0.650" lift. I don't like them because they look bad and can flex, but on the other hand they have less rotating inertia than most other rockers and they're inexpensive.

The drill on the pushrods is, you get a pair of checking or adjustable pushrods from a cam or pushrod company and use them to set your lifter preload how you want. Then you mail in the pushrods and they make (or pull off the shelf) a set. There are at least three ways to measure a pushrod and by doing what I have just described you can be assured of getting the right length.

It is also possible to run 16 adjustable pushrods, it was done all the time back in the day.

R.